SG Ready
SG Ready ("smart grid ready") gives a heat pump two control inputs. By switching them, an external device can tell the heat pump to hold back, run normally, or use extra energy while it is cheap or self-generated.
Two inputs, four states
Every RV model has SG Ready inputs. The common SG Ready convention defines four states from the two inputs:
| State 1 · Lock | Operation temporarily restricted, e.g. a utility block period |
|---|---|
| State 2 · Normal | Normal operation to the user's settings |
| State 3 · Recommended | Increased operation recommended: higher setpoints to store energy |
| State 4 · Forced | Run now: charge storage as far as the limits allow |
The terminals and the exact response of the controller in each state (which setpoints are raised, and by how much) are defined in the installation and controller documentation for the unit.
What the signal is used for
- Solar PV self-consumption: charge the hot water cylinder or buffer when panels produce a surplus. See heat pumps with solar PV.
- Time-of-use tariffs: store heat during cheap periods.
- Grid operator programmes: accept short lock periods where a local scheme offers a lower tariff for it.
Thermal storage makes it work
A signal is only useful if there is somewhere to put the heat. A hot water cylinder, a buffer tank and the thermal mass of an underfloor slab are the usual stores. The heat pump's maximum water temperature of 55 °C caps how much extra heat each store can take.
Compatibility
SG Ready is a contact interface, so any device with suitable switching outputs can drive it. Whether a specific utility programme, inverter or energy manager is supported has to be confirmed for that device and market.
Related: Solar PV integration · Smart Home Ready · RV series
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